Muscle from bone
A potential treatment
for heart failure relies
on stem cells from
bone marrow to renew
the heart’s pumping
tissue.

Ageneration ago, the battle to survive a heart attack was usu- ally won or lost in the emer- gencyroom. Medicaladvances
have now enabled more patients to win
that fight and go home from the hospital — but millions of them will face
another threat in the years to come.

The heart has a monstrous appetite

for fuel as it goes about pumping 2,500
gallons of blood a day. During a heart
attack, when an artery feeding heart
muscle gets choked off, the heart’s oxygen supply is interrupted. If starved of
oxygen for too long, a portion of the
heart can die, never to revive. Instead,
lifeless muscle will be gradually replaced
by an inflexible scar tissue not designed

Cellular injection The bone marrow
stem cells are injected via a catheter
into the heart either immediately
following a heart attack or once the
heart has become too weak and stiff
to pump properly.

for pumping blood. To compensate, the
remaining muscle pushes itself to work
harder. Eventually, the heart can grow
too stiff or too weak to efficiently eject
the blood flowing into it, and a person
lapses into heart failure.

Heart failure, a good portion of which
is caused by heart attack, has become
the leading reason older adults need